Dr Fátima Jorge beside the OMNI EM unit's Leica EMPact high pressure freezer.
Ever since Han Solo was frozen in carbonite in 1980, the science behind the science fiction of being cryogenically frozen has garnered public interest.
University of Otago Scientific Officer Richard Easingwood knows a thing or two about how and why scientists practice cryopreservation and has agreed to reveal the facts behind the fiction.
“In the face of certain mortality, it’s easy to see why some are tempted to hope that cryonics might one day allow for their entire frozen body, or just their head for the budget conscious, to be thawed and re-vitalised,” Richard says.
But he has bad news for those hopefuls.
“Despite the several hundred frozen bodies awaiting resurrection in cryonics companies there is zero proof that a whole human body can be revived,” he says.
“This science fiction plot device has existed since at least the 1960s but humans do not possess the necessary adaptations for this and so far the magic replacement for blood that might make this possible is likely yet to be invented despite optimistic claims by cryonics companies.”
Real cryopreservation is stopping the normal chemical processes that occur in cells by freezing them and it’s actually the easiest part of electron microscopy and cryonics, with the real challenge being stopping the creation of ice crystals during this, he says.
Richard Easingwood at the OMNI EM unit's JEOL 120kV transmission electron microscope.
When freezing, fluids inside and around the cells form ice crystals which grow like tiny knives, slicing through fine structures like cell membranes and damaging the specimens – this is why the texture of food that comes from the freezer compares poorly to that of fresh food.
Imagine placing a crisp piece of celery in a freezer for a day and then taking it out and letting it thaw. It will have lost its crispness due to ice crystals slicing through the cell walls.
Domestic freezers are still warm enough that ice crystals will continue to enlarge with time, which is why ice cream that was creamy when it’s first purchased becomes increasingly hard when left in the freezer.
The feasibility of cryogenics is compromised by the formation of ice crystals because a frozen human body, like a piece of celery, would be damaged by the ice crystals that formed when the body was frozen.
Crystal formation can be suppressed by either an extremely high pressure being applied during freezing or a very high freezing speed, both of which can be done with equipment available in the Otago Micro and Nanoscale Imaging (OMNI) unit.
Cryopreserving specimens in an undamaged state is crucial to any structural study because it allows researchers to see things as they really are without being destroyed or changed by ice crystals.
OMNI’s Electron Microscopy facility is available for use by internal and external researchers, working with both local and international researchers from other universities and research centres, commercial users and even individuals pursuing a research interest. Users from the Division of Health Sciences also benefit from a 75 per cent subsidy when using the facility.
Kōrero by the Division of Health Sciences Communications Adviser, Kelsey Swart.